kindling
by Pur Sang
Summary: The door is open, just a crack. He listens for a moment, unsure if she's in there or left the light on for him to find his way in the darkened, unfamiliar apartment. Nothing. Pushing it open cautiously, ever-so slowly, he stops cold at what he sees. / Episode insert for 2x17 (Tick, Tick, Tick...).
1. Chapter 1

It's as if everything owned by Kate Beckett was designed for his discomfort. The nasty spring in the Cruiser has a cousin that's taken residence in her couch, and it's just his luck that it digs into the same exact spot, too. Castle shifts around restlessly, growling to himself. It's not just the couch or the damn spring. It's the psychopath obsessed with his creation, who's stalking his muse. She said it's not his fault, that she doesn't blame him, but it doesn't change that she's the one in the crosshairs of an obsessive serial killer.

A small noise snaps his head up, an alert and excuse in one. Back creaking, he sits up, turning his head this way and that in an attempt to hear it again, to locate the sound's source. But all is calm. He thinks maybe his writer's imagination is running away with him again, inventing a noise to follow or a mystery to solve absent the ability to do anything about his real-life case. Perhaps a cool splash of water to his face will refresh him, and he can get a bit of writing done the old fashioned way, as sleep is not looking a viable option.

Lukewarm light from the bathroom warms the hallway, dimly illuminating in rust and sepia the framed photos chronicling all the things she's held dear. Memories. Family. Friends. Even, in group form, one containing him, half-buzzed and smiling broadly with his arm around Ryan as she pushes him playfully. Montgomery must have taken it, and he studies their rare, untroubled faces, remembering the night at a local cop bar fondly. Castle gazes at it a moment longer before shaking the wistfulness from his mind.

The door is open, just a crack.

He listens for a moment, unsure if she's in there or left the light on for him to find his way in the darkened, unfamiliar apartment. Nothing. Pushing it open cautiously, ever-so slowly, he stops cold at what he sees.

Her creamy skin is exposed inch by tantalizing inch as she pulls her top over her head, dropping the shirt onto her counter and pulling her arms above her head, examining herself in the mirror. Castle actually backs up a few inches, has one foot turned to move quietly as possible away from this moment he's intruding on, but he can't seem to make his knees bend right, or tear his eyes away. Her pink cotton bra is a crime; such pretty breasts ought not to be housed so plainly. But to him, it might as well be La Perla as he stands rooted to her floor, watching her turn to and fro.

Nimble fingers skate her sides and ribs, up, up toward the mounds of her breasts. Her delicate hands caress them, to cup the covered curves, critically studying her own image.

Castle struggles for air, balancing the need for oxygen with the need to stay quiet, all underlined by the rational part of his brain that remembers she sleeps with a gun. And besides that, that this is intensely disrespectful and wrong. It's something he's never wanted to be as a man, a person, a friend to her, but the willpower has just left him and he rationalizes it that he's not actually doing anything. Just watching, just his good-bad luck that he stumbled upon this.

Bluefire sparks of desire kindle through him, licking every nerve of his tensed body, betraying the better angels of his nature with baser instinct. His cock twitches, rapidly filling with all the blood that's drained from other parts of his body -– namely, his brain, since it can't seem to find enough energy to move his legs in a helpful direction such as away –- and he bites his tongue hard enough to wince in order to keep from making a sound.

She notices nothing. Practiced feminine fingers find their way behind her, flicking open the clasp of her bra and letting it fall down her thin arms. She throws it carelessly on the pile of her shirt on the counter, and Castle shudders at the view of her breasts. Contrary to his commentary, he's never cared much about size. Anything more than a mouthful is a waste, as far as he's concerned, and hers would make the most delectable mouthful: cream and perfect shape, the swelling tips of her nipples just the shade of vanilla-latte he'd always imagined. He knows they'd be every bit as delicious, if he had a ghost of a chance with her, chance enough to taste.

Which, when this inevitably goes south, he won't. He'll be lucky to leave alive at all. But what a way to go.

Kate cups her breast again, bare this time with stiffened peaks, and it occurs to him that she's not just undressing for bed. She's teasing herself. Arms pulled high over her head and locked behind, she poses like a pinup girl, chest jutting out. His mouth fills with the bitter taste of longing, tinged with fear and self-loathing.

Thumbs circle her areolae while her fingers spread and cage her breasts, teasing the sensitive undersides. Brushing over her nipples, she emits a tiny sound, pleasure restrained but clearly present. They stroke faster, more insistently circling the hard peaks while her fingertips knead the soft flesh beneath them. He can see her legs close tightly, then her abdomen clenches and she doubles up a bit, a sure sign of where all this pleasure is headed.

All at once, she abandons her pursuit as her breath grows harder, and for a split second he thinks he's been spotted, but her distraction is elsewhere. In a haste to divest herself, she flicks the button and pulls the zipper with a loud rasp of teeth unclenching, sliding her jeans down her long legs, panties coming with them. With a perverse rush, his keen attention to detail forces him to notice that the blacklace trimmed powder-pink silk is damp. She's exquisite. Castle unconsciously bites the knuckle of an index finger, needing something to ground what little control he has left. He's painfully hard, aching already to come, and then she bends over to pick up her jeans, showcasing her small but lush peach of an ass to his partial view.

It's positively adolescent, the way his hips buck at that sight.

Spidery fingerpads tapdance down her abdomen, playing around her hips, the kissable-bitable bones outlined in faint shadow there, visible but not unhealthily prominent as he thinks they may have been when they first met. Kate makes the most delicious _mmm_ sound, pressing her fingers there, gripping her own hips as a lover would from behind. Castle's large and weathered hands twitch and flex, wishing they could cover or replace hers.

One lithe foot with each toenail dressed in cantankerous claret picks up, flexes, sending the tendons in her calves. They're strong and more suited in their musculature to a ballerina than a cop, straining and shifting effortlessly under her skin. He can't fucking breathe. It's only worse as he travels upward. Her adorably –- go on, Castle, think it, it _is_ adorable -– knobby knees, remnant scars suggestive of an adventurous childhood of perhaps sidewalk scrapes and bicycle-accident bruises marring them and making them no less beautiful for it. He closes his eyes for strength at the study of the raw power in her thighs. And what's between them?

She turns a few degrees, displaying her uncovered sex to him in the mirror. Smooth and dusty-rose pink, her folds glistening with her arousal even before her first touch, her suckable clit already swollen and primed for touch. His mouth waters for it. He's wanted to taste her since the day they met. Run his then-stubbled cheeks across those thighs and lap at her until she screamed, and then keep going until she finally pushed his head away, too sensitive to continue.

A year later, that fantasy is still never far from the top of his mental inbox, and it returns to him in force now. He watches her caress herself, warm and light pressure over the planes of her abdomen, the fleshy curve of her ass, the coffee-dipped tips of her breasts. Her embrace is light, turned rough and grabby at points, then back again. Is this how she likes a lover's touch? Or would she never feel safe enough with another person to allow them the liberty to manhandle her, trust one enough to be sure they'd stop before the edge of too-far?

He turns away at the thought, mind over matter a little too late, but he'll step back while he can and salvage what willpower he does have, because he needs to be that for her. Safe. Trustworthy. He needs to stop, and he will. Not because it will give him a better chance with her, but because she's vulnerable and scared tonight and by some miracle, she trusts him to watch over her, be her backup. He's betrayed that enough by invading her precious privacy this far.

Heavily, he takes a stonelocked step back, his knees unwilling to work and his gait subsequently stiff. One last look, to memorize the once-in-a-lifetime-because-he's-never-getting-to-see-this-again expression on her face. Her versicolor eyes shutter open and closed, inky pupils black and blown. Her lips, large and worried from the bite of her own teeth, open just a fraction, and he wants to sample the taste of those, too. More than sample, in fact. Feast. He wants her mouth and he wants it now.

Watching her like this is disgusting and wrong. One more step back and his view is gone, but his guilty conscience comes knocking down the door now that some of the bloodflow –- not much, mind -– that went to his cock is released back to his upper brain.

He wishes he wasn't such a loser.

"Castle?"

* * *

_TBC. Please tell me what you think._

* * *

_Summer '14 Kink Meme  
Prompt: They aren't together, but somehow one of them ends up masturbating for the other.  
_


	2. Chapter 2

"Castle?" her voice calls, melody-sweet and exhaled and if he allows his imagination license, every bit as ditch-deep in arousal as he is. It stops him in his heavy track. He's been spotted. Shit shit shit shit shit shit shit, fuck-

And then she's there. He thinks of running but if she finds her gun, that's not going to be much of a help and besides he deserves whatever she's to inflict upon him. But nothing happens. She peers at him from behind the door.

"Wait," Beckett requests, breathless. Fuck, not Beckett. Not here, not like this. She's just Kate here. "No, wait," she asks again, more commanding. He stops his blind backing up, chances a look in her eyes, at last noticing they're fiery and stoked, not in pursuit of his blood, not in betrayal, but with violent arousal pouring off them.

Did she-?

"I knew you were there," she confirms it as if reading his thoughts, or maybe his slack and stupid expression says it all for him. "Come here, Castle." He doesn't move, can't, so she does, emerging from behind her shield of a door on full display for his hungry view. This time, he does groan aloud, a desperate and dark sound he only makes when he thinks of her in the more desperate moments of his life, stolen away in his office with his hand around his leaking cock. Only this time, it's over the real thing.

As she approaches, she reaches for him, little hand splaying across his bicep. An exhale escapes him. He has no clue what she wants, or what he's done, or why she's rewarding him for spying on her most intimate moments. But it's enough that she's not maiming him, so he stays where he is. Not that his disobedient body would allow him otherwise at this point.

She leans in, whispering dirtily in his ear as her bare breasts brush against him, only his thin t-shirt separating them. Nowhere near thick enough to stop his hypersensitive body from telling him just how much he appreciates the shivering drag of her nipples across his chest.

"I left the door open," confirmation, then, that she- what? Knew he'd come? That couldn't be true. Whatever his present perversions, his honest intent was only a cooling splash of water. "I hoped you'd- I waited. A while," she admits with a watery, self-deprecating sniff.

Castle finds his voice at last. "You wanted me to see that?" he asks lamely, only daring a shard of hope to the truth.

"Mmhm," the detective nods. "Please, don't go."

As if he could.

Her small hand slips into his larger one, a splendid-strange fit he's felt a couple of times before after a hard case or some petty fight when they've said things they do mean masquerading as things they don't mean. It's intended, he's sure, to reassure him, but all it does is ground him in the reality.

There's a psychopath on the loose, after her, inspired by his books, which he wrote as thinly-veiled, socially-acceptable fanfiction, about them. She puts on a brave front, as always, but she's scared. He's seen it in the way she moves, the hyperawareness, the way she twitches at every noise just as he does. She's vulnerable. She needs a friend, not a fuck.

"Beckett," he starts, vying for control of his emotions and libido, "no." It's the hardest single syllable he's ever forced out. His body jerks, cock unhelpfully twitching at the slight shift of his boxers, but he intends to ignore it.

"You don't want me?" Oh, and her voice is so hurt and insecure, lost and shamed, he can't allow that, can't watch her hurt on account of him.

"I do," Castle assures her, a panicky and humorless laugh at the irony of the situation escaping him, "you have no idea how much I want you, Kate," he wills her to believe him, letting his spare hand cup the baby-softness of her cheek, run the calluses of his thumb across her sculpted cheekbones in affection and admiration. "But not tonight. Not when we're both stressed and exhausted and not before we catch this one-man freak show that's running around gunning for the 'real' Nikki Heat."

Kate bites her lip, nodding almost imperceptibly as she accepts the truth in his words, but her eyes say she's going to fight just the same.

"I'm a big girl, Castle," she states primly, "I don't need a knight in tarnished armor. It's... convenient, tonight, with you already here, but," Beckett struggles with the admission, "you're not the only one who's thought of this, you know. Not the only one with fantasies."

Pressing herself flush to him so nothing – least of all the insistent poke of his painfully hard cock into her abdomen – is left to the imagination, she leans in and whispers to him.

"You're not the only one who wants to taste," her tongue clicks in his ear on the sharp tapping of the second t, and another chunk of his resolve breaks from land and slides helplessly into the sea. When he doesn't object further, she leads him and she lets him lead her back to the end of the hall, to her darkened room. She doesn't flick on the light. There's moonlight enough to glow her skin, snowy and stainless silver, save for the dark hair framing her face, and her hotcoal half-hooded eyes burning black and gray for him.

"Come here," she requests, perching herself on the small bed and motioning for him to join her. He hesitates, unsure if he should, but something in her voice says she'd very much like it if he did. So he does. She wastes little time on shyness or pretense, propping herself up with her ill-stuffed pillows before immediately returning to her breasts. Caressing them back into hard peaks, she rolls and pinches her nipples and he watches mesmerized, licking his lips at the thought of wrapping his mouth around her breast and letting his hand take over the rest.

"Feeling a little exposed here, Castle," Kate states coyly, "I'm naked and you're all buttoned up. Doesn't seem fair."

He's still not sure what's all going on here and the suspicion that she knocked him out some time ago and this is some sort of headwound-induced hallucination clings to him. He'd consider it more likely, if not for the lack of pain in his head and the distinct pain of his confined erection protesting at the seam in his jeans. Yanking his shirt over his head, he deposits it on the bed beside him, a noise of appreciation his reward and permission when her hands immediately seek him, touching this and that.

"I just need something good," she whispers to him, longing wrapped around every loose syllable. He hisses his pleasure when she circles his nipple, but he can't seem to make his leaden hands reciprocate, can't pull the strings to make the marionette of his body move.

Her tender-petal lips press to his and he opens for her, allows her tongue to swirl around his, to taste her for the first time. He's been so wrong, so wonderfully wrong, in his imaginings of her flavor. She tastes not of black cherries or sweet-tarts or Remy's strawberry shakes, but of dark vanilla coffee and hearthfire. Apples dusted with cinnamon. The expectant joy at the first turn of leaves, green to red in the fall.

It only takes once. Just like that, he's addicted.

Clever fingers work at his belt and jeans, and he has to take a few deep breaths, separating from the heroin of her taste to regain the remains of his control, let the part of his brain responsible for not being a sex-crazed, Beckett-craving fiend find foothold and remind him of why he's determined to wait for anything more than... what exactly are they doing, here?

Something good, she'd said. It worries him as much as excites. He can't have her hate him in the morning, for taking advantage. She's not out of her mind, not panicked and searching for absolution in sex, but that doesn't mean she's not compromised. The tension between them has been palpable from the first day they met, moreso than ever as their working trust and friendship has grown tender roots around it, perhaps somewhat in spite of it. The proximity, the pressures of the case, the near-boil state they've held themselves at ever since the kiss-that-almost-happened when he let it slip that she smelled like cherries – it all adds up to a situation with too much room for regret, if they do not tread carefully.

She needs this, yes, but she needs him to be her friend first. Castle swallows thickly, capturing her hand and drawing the line with determination, a centimeter shy of letting her touch him where his disobedient body craves her most.

"Another time," he promises, trying not to give in to her look of frustrated disappointment, the endearing pout he's sure shouldn't be so appealingly accordant with the smolder of her eyes, but fuck it, it is. Recapturing her lips, he swallows down her argument, his decision made. No further than some kissing and a mutually enjoyable show. "No need to rush."

Sighing with acceptance and what he suspects is even a little relief, Kate nods, touching her forehead to his own in search of comfort. Her inquisitive fingers retreat to her own person.

"Watch me, then," voice raspy, she parts her legs, giving him the most enticing view he's ever seen of her soaking thighs, the swollen bundle of nerves circled feather-lightly as she drags two fingers through her slit and makes the sweetest sound. "Join, if you like."

* * *

_TBC. Are we having fun yet?_


	3. Chapter 3

A year he's spent imagining this. His writer's mind has come up with a hundred ways it might happen. From the cloyingly romantic notions of winning her heart with flowers and gestures of affection like some awkward teenage imitation of courtly love, to the dark fantasies of carnality and use, disgusting and degrading to both, and everything in between. Nothing – _nothing_ – he could have imagined has come close to this.

The gift she's chosen to give him tonight is infinitely delicate and lovely. Her trust. Her vulnerability. He'll not take advantage of that. He will not fail.

Kate's back to stroking her inner thigh, the bony protrusions of her knuckles just grazing the neon white skin there. Her other hand reaches for his, and he looks to her eyes, asking permission despite the invitation. Her answer comes in the slip of her hand over his palm, the lace of her fingers through his as she guides them to her breast. Castle's eyes flutter closed for a moment, a soft groan escaping on an exhale.

"Watch me," she instructs, and his eyes open as if their lashed lids were attached to blind pulleys, as if her word has complete power over him. Maybe it does. Maybe it always has.

At first, he doesn't know where to look. The hand between her thighs creeps higher, caressing the lambsoft skin where her thigh creases to her pelvis. Her eyes, however – he never thought he'd have Kate Beckett touching herself for him and only be able to focus on her face.

"I wish these were your fingers..." she sighs, parting her folds. His eyes flicker downward. _God,_ she's wet, so perfect and pink and he wishes it was him touching her, too, but...

"What would you want me to do?" Castle asks. He won't break his promise, won't give in just yet, but this is the next best thing. "What do you imagine when you think about this?"

Two fingers plunge inside her and still. Her head jerks backward, eyes closing and her mouth gaping slightly open.

She hesitates, teeth worrying her bottom lip in a way that shouldn't be that enticing. "I... I think about you..." she stammers out at last, suddenly shy and self-conscious.

"Do you want to stop, Kate?" he asks, and he's more surprised to find he genuinely means his concern, that he can think of nothing worse in this moment than her being uncomfortable or feeling pushed. "We don't have to..."

Kate shakes her head, her vigorous denial bringing a bit of ease back into him. "I want to... I just- I've never done... _this_ for a man before. I didn't think... I thought you'd jump at the opportunity..."

Castle nods, dropping a kiss to her damp hair and shifting so that their naked hips touch again. "I thought I would, too," he admits with a hint of his normal humor, "It's a private thing, isn't it?"

"Yeah..." stroking her velvety outer lips with her fingertips, she resumes her attentions, just enough to tease herself, still shy. "I'm a little embarrassed..."

"You're absolutely gorgeous, Kate," he assures her, nuzzling the stony ridge of her jaw with his nose when inspiration strikes, "do you ever think about me doing this?"

She answers instantly. "Yes. Those scenes in Heat Wave obviously weren't written with your pants on. I pictured you in your office..." she trails off, and Castle smirks at how very rightly she's got him figured out.

"Does it embarrass you, to think about me doing this, then? That I think about you?"

"No. It's... it turns me on to think of you, thinking about me. But you're a man." As if it's just expected for him, and her pleasure has to be a shameful secret? He'll not have that.

Castle laughs, a breathless low sound from deep in his chest. "It makes no difference, Kate. What feels good feels good. Watching you touch yourself for me is a dream – and many, many daydreams – come true." She exhales beside him, a relieved laugh on the end of it, and she nods at last, her comfort and confidence returning. "So, you think about me?"

Her free hand smacks his bicep the way it often does when they're bickering playfully in front of the murder board, and the unexpected delight that they're still them even when they're doing this swells in his chest, a word he's not ready to acknowledge bubbling in his throat.

"I do."

Castle swallows thickly, stamping down the echoes of her affirmation his wildfire imagination manages to twist into a very different scenario. Shaking his head clear, he snickers, his hand wrapping lightly around his cock, not willing to further it yet.

"That's a good start. I'd be worried if you were telling me you thought about Esposito while we're doing this."

Giving a startled bark of a laugh, Kate smiles at him, her eyes opening and her shyness staved off. "Gross, Castle," she breaths, her fingers retreating from her body only to smear her slickness around, then returning slowly inside her. He watches her scissor them inside her. "If you were trying to buy a little more time here, that did it."

That wasn't precisely his goal, but she's not wrong, and more importantly, she's relaxed again, her fire back in force.

"I imagined you doing this," Beckett begins, smoke and sex creeping back into her lilted voice as she gains confidence again, "two of my fingers. One of yours."

"Good," Castle prods, rotating his palm loosely and shuddering when he follows her eyes to the movement of his hand, "tell me the story, Kate."

Kate lets out a melodious sound, something between a whimper and a sigh. Her thumb brushes her clit just once and the muscles in her abdomen jump. Fuck, she's close – already? He watches with fascination when she hovers her thumb again, but quickly abandons the bundle of nerves, already oversensitized.

"That- that day with Sorenson," Castle frowns. He does NOT want to hear about that. Isn't there a rule about mentioning exes in bed? "You were so jealous. So fired up. He kissed me and all I could think about was if it was you-" she sighs, "after you admitted to me that morning that you fantasized about me, that is."

"I did not!" He did, actually. But he can tell she's a little embarrassed, wondering whether this was a good idea, and bickering brings them back to a small semblance of normal, of putting her back in power.

"Did so-oh..." she tries to argue between gasps drawn by her lithe fingers. She dips into her wetness again, smearing it around her clit and drawing her lip between her teeth. Castle gives his hand a forceful jerk, twisting his sensitive foreskin over his shaft, the hand kneading her breast abandoning it for her face. His palm dwarfs her exquisite features, "you thought you played it so cool, when you caught us."

"I wanted to rip his head off," Castle confirms, flickering his eyes between the wet thrust of her digits into her own body – wishing to god they were his, but, no, there's good reason they're not doing that tonight – and watching her eyelids flutter at half-mast. He's taken most by the fascinating way her full, pink lips tremble like morning petals in the corners. The little noises she's making without seeming to notice it, on every breath between her increasingly disjointed words.

"God, Castle – I thought about telling him to go. That night, when that little girl was missing, I had to think of something – I thought about you. I thought about asking you home, stress relief, to feel something," Castle stops a moment, his rough strokes on his cock slowing. It's all too much like what's happening now, "I thought you were the only person on that case who felt worse than I did, the only person who understood, I wanted to go to you- I thought about you pushing me against the breakroom counter."

He groans at the visual. It's not a fantasy that exists solely in her mind. His hand resumes its pace, rough but not quite frantic, and the callused pad of his thumb brushes her sculpted cheekbone, urging her to look at him again.

"What did you want me to do?" he begs her raggedly. He needs the end, his mind craves it as much as his body craves release.

"I wanted you to push me against the counter and kiss me," Kate pants, her cheek feeling hot beneath his palm and the primal scent of her arousal flooding the air when she shifts, splaying her legs wider and plunging in and out, in and out. Transfixed, he gazes at the way he can see the muscles in the back of her hand and wrist flex, curling her fingers inside on every thrust, her thumb rubbing firey circles around her swollen clit now. Her words spill out now, practically a series of pleasured sobs, "Oh Castle, I wanted you to touch me, just like this, wanted your hands all over me, I wanted to be yours then, god, I'd had fantasies before... but that was when..."

What? What? He never finds out (and maybe it's better he doesn't, tonight), because suddenly there's no more words. Just a relieved, midnight cry of ecstasy and fullness and thoughtless release that he swallows into his mouth sealed over hers as he explodes, too enthralled by seeing and feeling and hearing Kate fall apart for him, admitting her most private fantasies for him. And only him.

* * *

Post-orgasmic Kate is beautifully unbeautiful. Blood pools in her cheeks, blotchy and flamed, turning pink and spreading all the way to her heaving chest. Her hair clings to the side of her face, messy and wild.

Her cooling, still-naked body pressing to his own, he's keenly aware of her thigh hooking over his, brushing innocent against his spent cock, the slick vee between her legs grazing against his hip, the first touch of their most intimate spaces. Her cheek resting on his shoulder. Her arousal-dampened fingers carding through his hair. The glow of her teeth in the dark when she smiles for him, the positively guileless giggle when he can't contain himself and kisses the tip of her nose.

He can't fucking _breathe._ She's gorgeous and undone and extraordinary and he can't help but think she's everything. But then, he knew that. He wouldn't be here if he didn't, but it'll take some time before he can deal with that.

Until he can, he has this.

There's the way she weasels into his embrace further and cuddles him shamelessly – not a behavior he'd ever have associated with her. But nothing else she's shown him tonight was expected either. There's the way world goes quiet for a while, reduced to her tender touches and his quest to kiss every inch of skin on her face.

There's her hesitant question, muffled by the skin of his shoulder, of whether they can do this again, whether he wants her again, and his whispered promise that they can, his assurance that he does. But only if she lets him take her to dinner before they debrief each other again. There's the roll of her eyes he senses rather than sees and her hum of agreement when she's too tired to respond properly and she's drifting to sleep, not entirely at peace but unburdened enough at least to rest.

There's the crisp weight of a light cotton blanket he pulls over them before he resumes his sleepless shift of watching and listening for what lurks in the shadows and still looms over them.

For now, there's just this and what they've done. And that's enough.

* * *

_Better late than never, yeah?_

_Please tell me what you think. I'll make no promises, but there may be a sequel of what happens after the events of "Boom." If you're good..._


End file.
